Polymorphs of methyl (E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phyenyl}-3-methoxyacrylate

ABSTRACT

The present invention relates to novel crystalline polymorphic and amorphous forms of the compound methyl (E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate (azoxystrobin). Infrared Raman spectra, X-Ray powder diffraction pattern and differential scanning calorimetry thermogram of two polymorphs “A” and “B” are provided. Further, the present invention also provides methods for preparing the novel polymorphic forms “A” and “B”, as well as processes for producing mixtures of the polymorphs, and a process for preparing amorphous azoxystrobin. Yet further, the present invention provides anti-fungal compositions comprising the novel crystalline polymorphs “A” and “B” or amorphous azoxystrobin, which are useful for controlling and combating fungi grown on agricultural and horticultural crops and up-land, and methods of using the same as pesticidal agents for combating fungi on agricultural and horticultural crops.

FIELD OF THE INVENTION

The present invention relates to novel crystalline polymorphs and anamorphous form of methyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate(azoxystrobin), to processes for their preparation, compositionscomprising the new forms, and their use as fungicidal agents.

BACKGROUND OF THE INVENTION

The strobilurin fungicide methyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate,known by the common name azoxystrobin, is a widely used commercialagrochemical product. It is described in “The Pesticide Manual”published by the British Crop Protection Council, 12th edition, pp.54-55 and in the proceedings of the Brighton Crop Protection Conference(Pests and Diseases) 1992, Volume 1, 5-6, pp. 435-442. It was firstdisclosed in EP-A-0382375 (compound 9, Example 3) along with methods forits preparation.

Azoxystrobin was first marketed in 1998 and is a systemic,broad-spectrum fungicide with activity against the four major groups ofplant pathogenic fungi including Ascomcetes (e.g., powdery mildews),Basidiomycetes (e.g., rusts), Deutoromycetes (e.g., rice blast) andOomycetes (e.g., downy mildew). It inhibits spore gemination andmycelial growth. It has worldwide uses on cereals, vines, rice, citrus,potatoes and tomatoes. In 1999, azoxystrobin was the leading proprietaryfungicide worldwide and is now a world market leader in cereals.

There are several reported ways of making azoxystrobin. Several methodsare based on the construction of the methyl α-phenyl-β-methoxyacrylategroup at an early stage followed by building the central pyrimidinyloxyand terminal cyanophenoxy rings. For example, (E)-methyl2-(2-hydroxyphenyl)-3-methoxyacrylate may be reacted with4,6-dichloropyrimidine under alkaline conditions inN,N-dimethylformamide to form (E)-methyl2-[2-(6-chloropyrimidin-4-yloxy)phenyl)-3-methoxyacrylate which is thenreacted with 2-cyanophenol in an Ullmann-type coupling process (seeEP-A-0382375). The (E)-methyl 2-(2-hydroxyphenyl)-3-methoxyacrylate maybe prepared by the formylation and subsequent methylation of methyl2-benzyloxyphenylacetate followed by removal of the benzyl protectinggroup (see EP-A-0242081). Formylation and methylation techniques forpreparing the methyl α-phenyl-β-methoxyacrylate group are also describedin WO 97/30020 and WO 97/01538.

U.S. Pat. No. 7,084,272 discloses an alternate method for preparingazoxystrobin by constructing the methyl α-phenyl-β-methoxyacrylate groupafter building on the central pyrimidinyloxy ring or the centralpyrimidinyloxy ring and terminal cyanophenol ring. Reportedly, thisavoids a Smiles-type rearrangement and delivers the desired E-isomer.

There is an urgent and unmet need in the art for efficient methods forthe preparation and purification of azoxystrobin, which are simple andcan be used on a large scale for industrial manufacture, and whichproduce highly pure product that can be safely utilized.

SUMMARY OF THE INVENTION

The present invention relates to novel crystalline polymorphic andamorphous forms of methyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate(azoxystrobin). The present invention also provides methods forpreparing the forms, as well as pharmaceutical compositions comprisingsame, and methods of using same as pesticidal agents for combating fungion agricultural and horticultural crops.

In one embodiment, the present invention provides a novel crystallinepolymorphic form of azoxystrobin, designated “Form A′”. Form A exhibitsan X-ray powder diffraction pattern substantially as shown in FIG. 1,having characteristic peaks (expressed in degrees 2θ (+/−0.2°θ) at oneor more of the following positions: 6.25, 13.8, 17.65, 19.05, 26.4, and28.5. Form A typically exhibits additional minor peaks at 11 and 14.4degrees 2θ (+/−0.2°θ). Form A also exhibits an infrared (IR) spectrumsubstantially as shown in FIG. 2, having characteristic peaks at about1378, 1328 and 1154 cm⁻¹. Form A also exhibits a Differential Scanningcalorimetry (DSC) thermogram substantially as shown in FIG. 3, which ischaracterized by a predominant endotherm peak in the range of about114-117° C. as measured by Differential Scanning calorimeter at a scanrate of 10° C. per minute. Form A also exhibits a Raman spectrumsubstantially as shown in FIG. 4, having characteristic peaks at about4398, 1329 and 2232 cm⁻¹.

In another embodiment, the present invention provides a novelcrystalline polymorphic form of azoxystrobin designated “Form B”. Form Bexhibits an X-ray powder diffraction pattern substantially as shown inFIG. 5, having characteristic peaks (expressed in degrees 2θ (+/−0.2°θ)at one or more of the following positions: 7.5, 11.75, 13.20 and 19.65.Form B typically exhibits additional minor peaks at 14.15, 17.1 and 23.6degrees 2θ (+/−0.2°θ). Form B also exhibits an IR spectrum substantiallyas shown in FIG. 6, having characteristic peaks at about 1389, 1335 and1245 cm⁻¹. Form B also exhibits a DSC thermogram substantially as shownin FIG. 7, which is characterized by a predominant endotherm in therange of about 101-105° C., as measured by Differential Scanningcalorimeter at a scan rate of 10° C. per minute. Form B also exhibits aRaman spectrum substantially as shown in FIG. 8, having characteristicpeaks at about 3098, 1335 and 2237 cm⁻¹.

In yet another embodiment, the present invention provides a mixture ofpolymorphic Form A and Form B of azoxystrobin. The mixture exhibits aDSC thermogram substantially as shown in FIG. 9, as measured byDifferential Scanning calorimeter at a scan rate of 10° C. per minute.

In another embodiment, the present invention provides a novel amorphousazoxystrobin, which exhibits an X-ray powder diffraction patternsubstantially as shown in FIG. 10.

In another aspect, the present invention provides processes forpreparing the novel polymorphs of azoxystrobin Form A and Form B, aswell as processes for producing mixtures of the polymorphs, and aprocess for preparing amorphous azoxystrobin.

In one embodiment, Form A azoxystrobin can be prepared by crystallizingazoxystrobin from a solvent selected from the group consisting analcohol, an ether, a ketone, an ester, an amide, a nitrile, and analiphatic or aromatic hydrocarbon; and isolating the resulting crystals.In a currently preferred embodiment, the solvent is selected from thegroup consisting of methanol, ethanol, tetrahydrofuran, acetone,ethylene glycol, acetonitrile, ethyl acetate, methyl isobutyl ketone,xylene and toluene. In another currently preferred embodiment, theprocess includes preparing a solution of azoxystrobin in one or more ofthe aforementioned solvents, preferably by applying heat untildissolution is complete, gradually cooling the solution until crystalsappear (e.g., by removing the heat and allowing the solution togradually cool), and isolating the crystals.

In one embodiment, Form B azoxystrobin can be prepared by crystallizingazoxystrobin from a solvent mixture comprising water and an organicsolvent selected from the group consisting of an alcohol and an amide;and isolating the resulting crystals. In a currently preferredembodiment, the organic solvent is selected from the group consisting of1-propanol and N,N-dimethyl acetamide. In another currently preferredembodiment, the process includes preparing a solution of the compound inone or more of the aforementioned organic solvents, with or withoutapplying heat until dissolution is complete, adding water (preferablypre-cooled) so as to form crystals of the compound, and isolating thecrystals.

In another embodiment, a mixture of Form A and Form B azoxystrobin canbe prepared by crystallizing azoxystrobin from a solvent mixturecomprising an alcohol (e.g., isopropyl alcohol, 1-propanol, and butanol)and an anti-solvent selected from an aliphatic and aromatic hydrocarbon(e.g., heptane); and isolating the resulting crystals. In a currentlypreferred embodiment, the process includes preparing a solution ofazoxystrobin in an alcohol, preferably by applying heat untildissolution is complete, adding the anti-solvent so as to form crystalsof the compound, and isolating the crystals. In another embodiment, amixture of Form A and Form B azoxystrobin can be prepared by a)preparing a solution of methyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylatein an alcohol (e.g., isopropyl alcohol); b) rapidly cooling the solutionso as to form crystals of said compound (e.g., by placing the solutionin a cold water or ice bath); and isolating the crystals.

In one embodiment, amorphous azoxystrobin is prepared by heatingazoxystrobin to a temperature greater than its melting point (preferablyto a temperature of about 120° C. or greater), and cooling as fast aspossible (e.g., quenching to ice-acetone bath).

In another aspect, the present invention provides anti-fungalcompositions comprising the novel crystalline polymorphs or amorphousazoxystrobin, which are useful for controlling and combating fungi grownon agricultural and horticultural crops and up-land. In one embodiment,the compositions comprise a crystalline polymorph Form A azoxystrobin;and an acceptable adjuvant. In another embodiment, the compositioncomprises a crystalline polymorph Form B of azoxystrobin; and anacceptable adjuvant. In another embodiment, the composition comprises amixture of a crystalline polymorph Form A and B of azoxystrobin; and anacceptable adjuvant. In one embodiment, the compositions comprise anamorphous azoxystrobin; and an acceptable adjuvant.

The present invention also relates to methods for combating fungus in aplant, comprising applying to the plant, to the seed of the plant or tothe locus of a seed or plant a fungicidally effective amount of thecompositions of the invention.

The present invention also relates to methods for protecting crops andupland, including industrial products thereof, such as seeds and fruits,by applying to the crops or products thereof an effective amount of thecompositions of the invention.

Further embodiments and the full scope of applicability of the presentinvention will become apparent from the detailed description givenhereinafter. However, it should be understood that the detaileddescription and specific examples, while indicating preferredembodiments of the invention, are given by way of illustration only,since various changes and modifications within the spirit and scope ofthe invention will become apparent to those skilled in the art from thisdetailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an X-ray powder diffraction spectrum of azoxystrobin Form A.

FIG. 2: is a FT Infrared spectrum of azoxystrobin Form A.

FIG. 3: is a Differential Scanning calorimetry (DSC) thermogram ofazoxystrobin Form A.

FIG. 4: is a Raman spectrum of azoxystrobin Form A.

FIG. 5: is an X-ray powder diffraction spectrum of azoxystrobin Form B.

FIG. 6: is a FT Infrared spectrum of azoxystrobin Form B.

FIG. 7: is a Differential Scanning calorimetry (DSC) thermogram ofazoxystrobin Form B.

FIG. 8: is a Raman spectrum of azoxystrobin Form B.

FIG. 9: is a Differential Scanning calorimetry (DSC) thermogram of anazoxystrobin Form a A and B mixture.

FIG. 10: is an X-ray powder diffraction spectrum of amorphousazoxystrobin.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is generally directed to novel crystallinepolymorphic forms of methyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate(azoxystrobin) referred to herein as “polymorph Form A” and “polymorphForm B”, and to mixtures of said polymorphs. The present invention alsorelates to an amorphous form of azoxystrobin. The present invention alsoprovides methods for preparing the novel polymorphs and amorphous form,as well as to pharmaceutical compositions comprising same, and methodsof use thereof for combating noxious livings on agricultural andhorticultural crops.

Solids exist in either amorphous or crystalline forms. In the case ofcrystalline forms, molecules are positioned in 3-dimensional latticesites. When a compound recrystallizes from a solution or slurry, it maycrystallize with different spatial lattice arrangements, a propertyreferred to as “polymorphism,” with the different crystal formsindividually being referred to as a “polymorph”. Different polymorphicforms of a given substance may differ from each other with respect toone or more physical properties, such as solubility and dissociation,true density, crystal shape, compaction behavior, flow properties,and/or solid state stability. In the case of a chemical substance thatexists in two (or more) polymorphic forms, the unstable forms generallyconvert to the more thermodynamically stable forms at a giventemperature after a sufficient period of time. When this transformationis not rapid, the thermodynamically unstable form is referred to as the“metastable” form. In general, the stable form exhibits the highestmelting point, the lowest solubility, and the maximum chemicalstability. However, the metastable form may exhibit sufficient chemicaland physical stability under normal storage conditions to permit its usein a commercial form. Furthermore, the metastable form, although lessstable, may exhibit properties desirable over those of the stable form,such as better formulative ability, improved dispersability in water andthe like.

To the applicant's best knowledge, in the case of methyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate(azoxystrobin), no crystalline forms are known.

The inventors of the present applications, after extensiveexperimentation, have discovered two new crystalline forms ofazoxystrobin, designated Form A and Form B. The inventors have furtherdiscovered a novel amorphous form of azoxystrobin. These new formsexhibit different spectral characteristics as depicted by their distinctDifferential Scanning calorimetry (DSC) thermograms, X-ray diffractionpatterns, infrared (IR) spectra and Raman spectra.

Form A

In one embodiment, the present invention provides a novel crystallinepolymorphic form of methyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate(azoxystrobin), designated “Form A”. This novel and surprising polymorphmay be characterized by, for example, by DSC. X-Ray powder diffractionspectrometry, IR spectrometry and/or Raman spectrometry.

For example, as shown in FIG. 1, Form A exhibits an X-ray powderdiffraction pattern having characteristic peaks (expressed in degrees2θ+/−0.2°θ) at one or more of the following positions: 6.25, 13.8,17.65, 19.05, 26.4, and 28.5. Form A typically exhibits additional minorpeaks at 11 and 14.4 degrees 2θ (+/−0.2°θ). The X-Ray powder diffractionwere collected on Philips powder diffractometer PW 1050/70 operated at40 kV and 30 mA using CuKαradiation (wavelength equal to 1.54178 Å) anddiffracted beam graphite monochromator. The typical θ-2θ scan range is3-35° 2 Theta with a step size of 0.05° and a count time of 0.5 secondsper step.

The samples were grinded using agate mortar and pestle. The obtainedpowder is then pressed into aluminum sample holder with rectangularcavity of 20 mm*15 mm and of 0.5 mm depth.

Furthermore, as shown in FIG. 2, Form A also exhibits an Infrared (IR)spectrum having characteristic peaks at about 1378, 1328 and 1154 cm⁻¹,as measured by a Fourier transform infrared (FT-IR) spectrophotometerReactIR™ 1000 of Mettler Toledo Autochem (ATR method, MCT detector),diamond window, in DuraSamplIR™ sampling device. The diamond sensor hasa standard focusing optic of ZnSe. The powdered samples were compressedin the sampling device and were measured with resolution of 4 cm⁻¹ and256 scans.

Furthermore, as shown in FIG. 3, Form A also exhibits a DifferentialScanning calorimetry (DSC) thermogram which is characterized by apredominant endotherm peak at a range of about 114-117° C. as measuredby DSC of Mettler Toledo with 821^(e) module. The weighted samples (2-4mg) were purged with nitrogen flow during the measurements at a scanrate of 2 and/or 10° C. per minute. Aluminum standard pierced cruciblesof 40 μL were used. The evaluation is performed using STAR^(e.)software. As used herein, the term “about 114-117° C.” means a range of110° C. to 120° C. In this regard, it should be understood that theendotherm measured by a particular differential scanning calorimeter isdependent upon a number of factors, including the rate of heating (i.e.,scan rate), the calibration standard utilized, instrument calibration,relative humidity, and upon the chemical purity of the sample beingtested. Thus, an endotherm as measured by DSC on the instrumentidentified above may vary by as much as ±1.5° C.

Furthermore, as shown in FIG. 4, Form A also exhibits a Raman spectrumhaving characteristic peaks at about 4398, 133029 and 22332 cm⁻¹. Ramanspectra were monitored using a confocal Raman microscope (Jobin YvonLabram UV HR), driven by Labspec 4.04 software. In this system the Ramanspectrometer is coupled to a microscope (Olympus BX 41). Ramanscattering was excited by a diode laser at 784.79 nm with laser power ofabout 10 mW. The scattered light was then focused into a 0.8 mdispersive spectrometer, equipped with a 600 lines/mm grating andcombined with an air cooled charged coupled device (CCD) for Ramansignal detection. Spectra were monitored by focusing the laser beammanually on particular points in the crystals. The focusing was done byan ×50/0.75 microscope objective to spots of ˜1.5 μm diameter. Aconfocal pinhole of 100 μm diameter, before the entrance slit to thespectrograph, rejected fluorescence and Raman signal from out of focusplanes. The spectra were collected in the 150-3500 cm⁻¹ range, whilescanning the spectrum across the CCD by moving the grating seven times.The different spectral regions were accumulated over 180 s and each ofthem twice. The spectra were corrected for the contribution of thefluorescence background (not shown).

In another aspect, the present invention provides processes forpreparing the novel azoxystrobin polymorph Form A. Form A azoxystrobincan be prepared by crystallizing azoxystrobin from a solvent selectedfrom the group consisting an alcohol, an ether, a ketone, an ester, anamide, a nitrile, and an aliphatic or aromatic hydrocarbon; andisolating the resulting crystals. In a currently preferred embodiment,the solvent is selected from the group consisting of methanol, ethanol,tetrahydrofuran, acetone, ethylene glycol, acetonitrile, ethyl acetate,methyl isobutyl ketone, xylene and toluene. In another currentlypreferred embodiment, the process includes preparing a solution of thecompound is one or more of the aforementioned solvents, preferably byapplying heat until dissolution is complete, gradually cooling thesolution until crystals appear, and isolating the crystals. Generally,cooling to room temperature is sufficient, however, the solution can becooled to lower temperatures, for example 0° C., 5° C., 10° C., 15° C.and the like. Gradual cooling is typically achieved e.g., by removingthe heat and allowing the solution to cool.

Also, the reaction can be seeded with Form A seeds in order to inducecrystallization, as known in the art.

The azoxystrobin starting material used for preparing Form A can be anyform of azoxystrobin, including azoxystrobin prepared in accordance withEP-A-0382375, EP-A-0242081 or U.S. Pat. No. 7,084,272, amorphousazoxystrobin, azoxystrobin Form B, a mixture of azoxystrobin Form A andForm B, or any other azoxystrobin known in the art.

Form B

In another embodiment, the present invention provides a novelcrystalline polymorphic form of methyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate(azoxystrobin), designated “Form B”. This novel and surprising polymorphmay be characterized by, for example, DSC, X Ray powder diffractionspectrometry IR spectrometry and/or Raman spectrometry.

For example, as shown in FIG. 5, Form B exhibits an X-ray powderdiffraction pattern having characteristic peaks (expressed in degrees 2θ(±−0.2° θ) at one or more of the following positions: 7.5, 11.75, 13.20and 19.65. Form B typically exhibits additional minor peaks at 14.15,17.1 and 23.6 degrees 2θ (+/−0.2 θ). The X-Ray powder diffraction wasmeasured as described above.

Furthermore, as shown in FIG. 6, Form B also exhibits an Infrared (IR)spectrum having characteristic peaks at about 1389, 1335 and 1245 cm⁻¹,as measured by a Fourier transform infrared (FT-IR) spectrophotometer asdescribed above.

Furthermore, as shown in FIG. 7, Form B also exhibits a DSC thermogramwhich is characterized by monotropic system showing a predominantendotherm at a range of about 101-105° C. The thermogram was measured bya Differential Scanning calorimeter as described above. As used herein,the term “about 101-105° C.” means from 97° C. to about 108° C.

Furthermore, as shown in FIG. 8, Form B also exhibits a Raman spectrumhaving characteristic peaks at about 3098, 1335 and 2237 cm⁻¹, measuredby the method described above.

In another aspect, the present invention provides processes forpreparing the novel polymorph Form B. Form B can be prepared bycrystallizing azoxystrobin from a solvent mixture comprising water andan organic solvent selected from the group consisting of an alcohol andan amide; and isolating the resulting crystals. In a currently preferredembodiment, the organic solvent is selected from the group consisting of1-propanol and N,N-dimethyl acetamide. In another currently preferredembodiment, the process includes preparing a solution of the compound inone or more of the aforementioned organic solvents, with or withoutapplying heat until dissolution is complete, adding water, preferablypre-cooled so as to form crystals of the compound, and isolating thecrystals. Generally, the water is pre-cooled for example to 0° C., 5°C., 10° C., 15° C. and the like.

The azoxystrobin starting material used for preparing Form B can be anyform of azoxystrobin, including azoxystrobin prepared in accordance withEP-A-0382375, EP-A-0242081 or U.S. Pat. No. 7,084,272, amorphousazoxystrobin, azoxystrobin Form A, a mixture of azoxystrobin Form A andForm B, or any other azoxystrobin known in the art.

Form A and Form B Mixtures

In yet another embodiment, the present invention provides a mixture ofpolymorphic Form A and Form B of methyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate(azoxystrobin).

The mixture exhibits a Differential DSC thermogram substantially asshown in FIG. 9, as measured by Differential Scanning calorimeter asdescribed above.

In another aspect, the present invention provides processes forpreparing a mixture of azoxystrobin Form A and Form B. A mixture of FormA and Form B azoxystrobin can be prepared by crystallizing azoxystrobinfrom a solvent mixture comprising an alcohol (e.g., isopropyl alcohol,1-propanol and butanol) and an anti-solvent selected from an aliphaticand aromatic hydrocarbon (e.g., heptane); and isolating the resultingcrystals. In a currently preferred embodiment, the process includespreparing a solution of azoxystrobin in an alcohol, preferably byapplying heat until dissolution is complete, adding the anti-solvent soas to form crystals of the compound, and isolating the crystals. Thereaction can also be cooled to induce precipitation. Generally, coolingto room temperature is sufficient, however, the solution can be cooledto lower temperatures, for example 0° C., 5° C., 10° C., 15° C. and thelike.

In another embodiment, a mixture of Form A and Form B azoxystrobin canbe prepared by a) preparing a solution of methyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylatein an alcohol (e.g., isopropyl alcohol); b) rapidly cooling the solutionso as to form crystals of said compound; and isolating the crystals. By“rapid cooling” it is meant that the solution is contacted with a coldmedium (e.g., a chilled water bath or an ice bath) so as to achieve arapid decrease in temperature which induced formation of crystalscomprising a mixture of Form A and Form B azoxystrobin. The azoxystrobinstarting material used for preparing the Form A and Form B mixture canbe any form of azoxystrobin, including azoxystrobin prepared inaccordance with EP-A-0382375, EP-A-0242081 or U.S. Pat. No. 7,084,272,amorphous azoxystrobin, azoxystrobin Form A, azoxystrobin Form B, or anyother azoxystrobin known in the art.

Amorphous Azoxystrobin

In another embodiment, the present invention provides a novel amorphousazoxystrobin. This novel and surprising amorphous form may becharacterized by, for example, X-Ray powder diffraction spectrometry.

For example, as shown in FIG. 10, the amorphous form has an X-ray powderdiffraction pattern showing no significant signals, indicating anamorphous azoxystrobin solid.

In another aspect, the present invention provides processes forpreparing the novel amorphous azoxystrobin. In one embodiment, amorphousazoxystrobin is prepared by heating azoxystrobin to a temperaturegreater than its melting point (preferably to a temperature greater thanabout 100° C., more preferably to a temperature of about 120° C.), andvery fast cooling (e.g. quench cooling).

The azoxystrobin starting material used for preparing the amorphousazoxystrobin can be any form of azoxystrobin, including azoxystrobinprepared in accordance with EP-A-0382375, EP-A-0242081 or U.S. Pat. No.7,084,272, azoxystrobin Form A, azoxystrobin Form B, mixtures of Form Aand Form B, or any other azoxystrobin known in the art.

Compositions and Uses

Azoxystrobin is known to impart excellent effect for combating noxiouspests including, but not limited to: Anthracnose (Colletotrichumgraminicola), Brown Patch (Rhizoctonia solani), Cool Weather Brown Patch(Rhizoctonia cerealis), Fusarium Patch (Microdochium nivale), Gray SnowMold (Typhula spp.), Leafspot (Drechslera spp. and/or Bipolaris spp.),Melting Out (Drechslera spp. and/or Bipolaris spp.), Necrotic Ring Spot(Leptosphaeria korrae), Pink Snow Mold (Microdochium nivale), PythiumBlight (Pythium spp.), Pythium Root Rot (Pythium spp.), Red Thread(Laetisaria fuciformis), Rhizoctonia Large Patch (Rhizoctonia solani),Spring Dead Spot (Leptosphaeria korrae or Gaeumannomyces graminis),Summer Patch (Magnaporthe poae), Take-all Patch (Gaeumannomycesgraminis), Yellow Patch (Rhizoctonia cerealis), and Zoysia Patch(Rhizoctonia solani and/or Gaeumannomyces incrustana), Ascomcetes (e.g.,powdery mildews), diomycetes (e.g., rusts), Deutoromycetes (e.g., riceblast) and Oomycetes (e.g., downy mildew).

Thus, in one embodiment, the present invention also providescompositions comprising the novel crystalline polymorphs or amorphousforms, which are useful for controlling and combating noxious livinggrown on agricultural and horticultural crops and up-land, especiallyfungus. In one embodiment, the composition comprises a crystallinepolymorph Form A of azoxystrobin; and an acceptable adjuvant. In anotherembodiment, the composition comprises a crystalline polymorph Form B ofazoxystrobin and an acceptable adjuvant. In yet another embodiment, thecomposition comprises a mixture of a crystalline polymorph Form A andForm B of azoxystrobin; and an acceptable adjuvant. In one embodiment,the composition comprises amorphous azoxystrobin; and an acceptableadjuvant.

The present invention also relates to methods for combating fungus,comprising applying to a plant, to the seed of the plant or to the locusof a seed or plant a fungicidally effective amount of the compositionsof the invention.

The present invention also relates to methods for protecting crops andupland, including industrial products thereof, such as seeds and fruits,by applying to the crops or products thereof an effective amount of thecompositions of the invention.

The concentration of the azoxystrobin for use in the compositions of thepresent invention will depend upon object noxious livings, the method ofapplication, and the form of the composition and the dose of the activeingredient. The concentration is not critical and it is usually in arange of about 1 to 10,000 ppm, preferably about 20 to 2,000 ppm.

The composition can be prepared in a variety of forms such as dust,wettable powder, emulsifiable concentrate, inert emulsion, oil solution,aerosol preparation, etc. with adjuvants as the cases of agriculturalcompositions. The composition can be applied with or without dilutingthem in suitable concentrations.

Suitable adjuvants include powdery carries such as talc, kaolin,bentonite, diatomaceous earth, silicon dioxide, clay and starch; liquiddiluents such as water, xylene, toluene, dimethylsulfoxide,dimethylformamide, acetonitrile, and alcohol; emulsifiers dispersingagents, surfactants such as sodium alkyl benzene sulfonate,polyoxyethylene alkylaryl ether, sodium naphthalene sulfonateformaldehyde condensate, calcium ether sulfate, polyoxyethyleneglycoldodecylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene fattyacid ester, sodium alkylsulfate, sulfate of polyoxyethylene alkylarylether and di-alkylsulfosuccinate etc.

The concentration of the active ingredient in the composition is usually5 to 80 wt. % in the case of the oily concentrate; and 0.5 to 30 wt. %in the case of dust; 5 to 60 wt. % in the case of wettable powder. It isalso possible to combine with the other agricultural ingredients such asthe other insecticides, acaricides, and/or plant growth regulators.Sometimes synergistic effects are found. The other agriculturalingredients include organic phosphoric acid ester type compounds,carbamate type compounds, dithio (or thiol) carbamate type compounds,organic chlorine type compounds, dinitro type compounds, organic sulfuror organometallic type compounds, antibiotics, substituted diphenylether type compounds, urea type compounds, triazine type compounds,benzoylurea type compounds, pyrethroid type compounds, imide typecompounds and benzimidazole type compounds and more particularly,benzoylurea type insecticides such asN-(2,6-difluorobenzoyl)-N′-(p-chlorophenyl)urea; pyrethroid typeinsecticides such as .alpha.-cyano-3-phenoxybenzyl-2-(4-chlorophenyl)isovalerate; imide type germicides such asN-(3,5-dichlorophenyl)-1,2-dimethylcyclopropane-1,2-dicarboximide;benzimidazole type germicides such asmethyl-1-(butylcarbamoyl)-2-benzimidazolecarbamate; thio carbamate typegermicides such as S-ethyl N-(3-dimethylaminopropyl)thiocarbamatehydrochloride; dithiocarbamate type germicides such as manganeseethylenebisdithiocarbamate; and urea type germicides such as2-cyano-N-(ethylamino carbonyl)-2-(methoxyimino)acetamide.

The following examples are presented in order to more fully illustratecertain embodiments of the invention. They should in no way, however, beconstrued as limiting the broad scope of the invention. One skilled inthe art can readily devise many variations and modifications of theprinciples disclosed herein without departing from the spirit and scopeof the invention.

EXPERIMENTAL DETAILS SECTION Example 1 Preparation of Azoxystrobin FormA

Azoxystrobin (10 g.) was dissolved in 50 ml. of isopropyl alcohol inErlenmeyer with magnetic stirring at reflux for 10 minutes. Theresulting clear solution was slowly cooled to 54° C. and left at thattemperature for 10 minutes. The resulting crystalline solid was filteredand dried at 40° C. in the oven.

Example 2 Preparation of Azoxystrobin Form A

Azoxystrobin was crystallized from the solvents listed in Table 1.Azoxystrobin is crystallized by forming a clear solution of Azoxystrobinby heating to reflux for 1-2 hrs. The solution was then cooled to roomtemperature and the forming crystals were filtered out and dried in theoven at 40-50° C. for 24 hrs.

TABLE 1 Ratio of solvent Solvent (ml):Azoxystrobin (g) Precipitationtime Ethanol 9 Rapid Methanol 7.5 1 day Tetrahydrofuran 5 Rapid Acetone2.5 Rapid Ethylene glycol 5 Rapid Acetonitrile 5 Rapid Ethyl acetate 5Rapid Methyl Isobutyl Ketone 5 3 days Xylene 5 Rapid Toluene 2.8 Rapid

Example 3 Preparation of Azoxystrobin Form B

Azoxystrobin (2 g.) was dissolved in 10 ml of isopropyl alcohol inErlenmeyer at reflux for 1 hour with vigorous magnetic stirring. Thesolution was then removed from the heating plate and cold water weredosed until cloud point (7.3 g.). The resulting light slurry was cooledto RT and the white crystalline matter was filtered out and dried at 40°C. in the oven.

Example 4 Preparation of Azoxystrobin Form B

Azoxystrobin (2 g.) was dissolved in 10 ml of 1-Propanol in Erlenmeyerat reflux for 1 hour with vigorous magnetic stirring. The solution wasthen removed from the heating plate and cold water were added untilcloud point and beyond it (15.6 g). The resulting light slurry wascooled to RT and the white crystalline matter was filtered out and driedat 40° C. in the oven.

Example 5 Preparation of Azoxystrobin Form B

Azoxystrobin (162 g.) was added to 300 g. of N,N-Dimethyl acetamide in areactor of 1 liter at 500-850 rpm and 25° C. After the completion of thedissolution, 200 g. of water were dosed during 20-120 minutes. Theslurry was stirred for 15 minutes and filtered out. The filtered solidwas dried at 40° C. in the oven.

Example 6 Preparation of a Mixture of Azoxystrobin Form A and Form B

Azoxystrobin (2.1 g.) were dissolved in 12 ml of isopropyl alcohol inErlenmeyer at reflux for 1 hour, with magnetic stirring. At theseconditions, 7 ml of n-Heptane were added dropwise and the Erlenmeyer wasremoved from the heating plate. After 3 minutes the solution becomescloudy. After cooling to RT the resulted slurry was filtered out anddried at 40° C. in the oven.

Example 7 Preparation of a Mixture of Azoxystrobin Form A and Form B

Azoxystrobin (2.1 g.) were dissolved in 12 ml of Butanol in Erlenmeyerat reflux for 1 hour, with magnetic stirring. At these conditions, 7 mlof n-Heptane were added dropwise and the Erlenmeyer was removed from theheating plate. After 2 minutes the solution becomes cloudy. Aftercooling to RT the resulted slurry was filtered out and dried at 40° C.in the oven.

Example 8 Preparation of a Mixture of Azoxystrobin Form A and Form B

Azoxystrobin (2 g.) were dissolved in 10 ml Isopropyl alcohol at refluxin Erlenmeyer with magnetic stirring for 10 minutes. The solution wasremoved from the heating plate and at a temperature of 67° C. the cloudysolution was transferred to ice-water medium bath for rapid cooling. Theresulting slurry was then filtered out and the crystalline matter wasdried at 40° C. in the oven.

Example 9 Preparation of Amorphous Azoxystrobin

Azoxystrobin (1 g.) was heated in a 250 ml beaker over heating plateuntil melt. The hot magma (at ˜120° C.) was kept heated for further 10minutes and then immediately placed in an ice-acetone bath (−15° C.) forrapid cooling. The amorphous glass-like solid was analyzed in X-raypowder diffraction. The obtained difractogram exhibit no distinct peaks.

While certain embodiments of the invention have been illustrated anddescribed, it will be clear that the invention is not limited to theembodiments described herein. Numerous modifications, changes,variations, substitutions and equivalents will be apparent to thoseskilled in the art without departing from the spirit and scope of thepresent invention as described by the claims, which follow.

The invention claimed is:
 1. A mixture of crystalline polymorphic Form Aand Form B of methyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate,wherein Form A exhibits an X-ray powder diffraction pattern havingcharacteristic peaks expressed in degrees 20 (+/−0.20°θ) at about 6.25,13.8, 17.65, 19.05, 26.4, and 28.5, and Form B exhibits an X-ray powderdiffraction pattern having characteristic peaks expressed in degrees 20(+/−0.20°θ) at about 7.5, 11.75, 13.20 and 19.65.
 2. The mixtureaccording to claim 1, which exhibits a Differential Scanning calorimeter(DSC) thermogram substantially as shown in FIG.
 9. 3. A process forpreparation of a mixture of a crystalline polymorph Form A and Form B ofmethyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylateaccording to claim 1, the process comprising a) crystallizing saidcompound from a solvent mixture comprising an alcohol and ananti-solvent selected from aliphatic and aromatic hydrocarbon; and b)isolating the resulting crystals.
 4. The process according to claim 3,wherein the alcohol is selected from the group consisting of isopropylalcohol, 1-propanol, and butanol.
 5. The process according to claim 3,wherein the anti-solvent is heptane.
 6. The process for the preparationof a mixture of a crystalline polymorph Form A and Form B of methyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylateaccording to claim 3, the process comprising a) preparing a solution ofmethyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylatein an alcohol; b) adding an anti-solvent selected from aliphatic andaromatic hydrocarbon to said solution so as to form crystals of saidcompound; and c) isolating the crystals.
 7. A process for thepreparation of a mixture of a crystalline polymorph Form A and Form B ofmethyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylateaccording to claim 1, the process comprising a) preparing a solution ofmethyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylatein an alcohol; b) rapidly cooling the solution so as to form crystals ofsaid compound; and c) isolating the crystals.
 8. The process accordingto claim 7, wherein the alcohol is isopropyl alcohol.
 9. A compositionfor combating fungus which comprises a mixture of crystalline polymorphForm A and B of methyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylateaccording to claim 1, and an acceptable adjuvant.
 10. A method forcombating fungus in a plant, comprising applying to the plant, to a seedof the plant or to a locus of the seed or the plant a fungicidallyeffective amount of the composition of claim
 9. 11. A method forprotecting crops from fungus, comprising applying to the crops aneffective amount of the composition of claim
 9. 12. A composition forcombating fungus which comprises a mixture of crystalline polymorph FormA and B of methyl(E)-2-{2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl}-3-methoxyacrylateaccording to claim 2, and an acceptable adjuvant.
 13. A method forcombating fungus in a plant, comprising applying to the plant, to a seedof the plant or to a locus of the seed or the plant a fungicidallyeffective amount of the composition of claim
 12. 14. A method forprotecting crops from fungus, comprising applying to the crops aneffective amount of the composition of claim
 12. 15. The mixtureaccording to claim 1, wherein the polymorph Form A further exhibitsX-ray powder diffraction characteristic peaks expressed in 20(+/−0.20°θ) at about 11 and 14.4.
 16. The mixture according to claim 1,wherein the polymorph Form A exhibits an infrared (IR) spectrum havingcharacteristic peaks at about 1378, 1328, 1154 cm⁻¹.
 17. The mixtureaccording to claim 1, wherein the polymorph Form A exhibits a singlepredominant endotherm at a range of about 114-117°C as measured by aDifferential Scanning Calorimeter (DSC) at a scan rate of 10°C perminute.
 18. The mixture according to claim 1, wherein the polymorph FormA exhibits a Raman spectrum having characteristic peaks at about 4398,133029 and 22332, substantially as shown in FIG.
 4. 19. The mixtureaccording to claim 1, wherein the polymorph Form B further exhibitsX-ray powder diffraction characteristic peaks expressed in 20(+/−0.20°θ) at about 14.15, 17.1 and 23.6.
 20. The mixture according toclaim 1, wherein the polymorph Form B exhibits an infrared (IR) spectrumhaving characteristic peaks at about 1389, 1335, 1245 cm³¹ ¹.
 21. Themixture according to claim 1, wherein the polymorph Form B exhibits apredominant endotherm at a range of about 101-105°C as measured by aDifferential Scanning Calorimeter (DSC) at a scan rate of 10°C perminute.
 22. The mixture according to claim 1, wherein the polymorph FormB exhibits a Raman spectrum having characteristic peaks at about 3098,1335 and 2237 cm⁻¹, substantially as shown in FIG. 8.